Air pump



Jan. 15 1924. 1,481,070

I y J. nsHr-:VLIN

AIR PUMP l i Filed July l0 1922 Patented dan., l5, 1924.

JOSEPH. P. SHEVLIN, OF DENVER, COLORADO.

AIR PUMP.

Application filed July 10, 1922. Serial No. 574,051.

To all whom it may concern:

Be it known that I, JOSEPH P. SHEVLIN, a citizen of the United States, residing at the city and county of Denver and State of Colorado, have invented certain new and useful Improvements in Air IBumps; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this speciiication.

This invention relates to pumps, and has special reference to improvements in the construction of vportable air pumps of the types used for inliating tires.

Air pumps are old and well known and one is carried by practically every automo bile. All the pumps with which I am lac-` quainted are provided with leather cups which serve as valves and pistons. The air usually enters the cylinder of the pump between the cylinder wall and the leather cup. This is made possible by thev fact that the leather cups are, as their names imply, cupshaped, and offer little or no resistance to the passage of air in one direction, but act as almost positive stops to the movement of air in the other direction. The passage of the air between the cup-shaped valves and the sides of the cylinder tends to dry the leather and make it brittle. A great deal of the trouble experienced with air pumps is due to the drying out and the cracking of the leather caused by the passage of the air as pointed out above.

It is the object of this invention to overcome the objection referred to above, and for this purpose I modify the construction of the valves in such a manner that the air will not have to enter the piston chamber by passing between the cylinder walls and the piston, but through openings provided therefor.

In order to more clearly describe my invention, I shall have reference to the accompanying drawing, in which Fig. 1 is an elevation of my pump with parts thereof broken away to show the relative positions of the various parts;

Fig. 2 is a vertical section of my pump taken on line 2-2, Fig. 1;

Fig. 3 is a plan view of one of the valve members;

Fig. 4: is aside elevation thereof;

F ig. 5 is a plan view of another valve member; and

Fig. 6 is a side elevation of the member shown in Figr.

rlhe same reference numerals will be used to indicate the same parts throughout the several views.

My central hollow boss 2 extending upwardly from one side thereof. rIhe inside of boss 2 is threaded andthe sides thereof are pro; vided with an opening 3 for the reception of a'hose coupling 4. A ltube 5 of brass or any other suitable material has its lower end threadedly connected to boss 2 in the manner indicated in Fig. 2; this pipe forms lthe high pressureV cylinder of the pump. Secured to theupper end of tube 5 is a cap 6, which is shown in lan and side elevation in Figs. 5 and 6. ap 6 has `a threaded flange 7 which engages cooperating threads on the end of 'tube 5. A threaded stud 8 projects upwardly from the center of cap 6.. Lugs 9 extend radially from stud 8 and are spaced angularly about 90 degrees apart. Shoulders 10 are formed a short distance above the upper surface of cap 6 and" serve as supports for the valve 11 which will be described more in detail hereinafter. The

pump consists of a base 1 having a` ool soV

vertical sides 12 form guides for valve 11.

A leather washer'13 is placed on the stud 8 and clamped against the 'upper' shoulders 111 by means of a nut 15. I-Ioles 16 extend through the cap 6 and constitute the passages through which the air `passes from the V Y low pressure cylinder to the high pressure cylinder when the pump lis operated in the manner to be hereinafter described.

Valve 11 consists of a leather cup 17 clamped between the sides ofthe ring -18` which maybe formed in any suitable manner, but which is preferably pressed out of a single piece of metal of the cross section substantially like that shown. The length of the guiding shoulders 12 is greater than the thickness of valve 11, with the result that the latter is free toslide thereon and ma occupy the position Ashown in full lines in 1ig. 2, or the position shown `dotted in the same figure. Cap 6 has an axial hole 19 through which rod 20 slides with a close fit- Secured tothe lower end of rod 2O is the high pressure piston and valve which comprises a valve member 21 having a leather cup 22 secured thereto in the same manner at the lower end of. which there is an annular flange 26 provided with a plurality of spaced holes 27. Thevalve 21 is held in place onstem 25by means of theliange 26 and nut 23. A leather washer 2 8separates the valve 21 from the nut 23 and vserves to form a seal when the valve 21 .operates to compress the air. To the lower end of tube 29 I secure a cap 30 which has a central opening of a diameter equal to that of pipe 5. .A downwardly extending cylindrical flange 31k is internally screw-threaded for the reception of a gland 32 which serves to compress the packing material 33 by means of which an .airtight sliding connection is made with tube 5. To the top of tube 29 I secure va cap 34 which ,has centrally thereof an upwardly projecting threaded boss 35 which engages corresponding threads onrod 20. Cap 34 is also provided with a .number of openings 36. The upper threaded end of rod 2O extends vupwardly through a handle 37 which is held in place thereon by means of anut 38. v

The operation of the pump is as follows: The pump is connected to the `valve stem of the tirel in the usual way. The. operator then holds the base 1 down by means ofhis feet and grasping the handle 37 heraises the latter. As tube 5 is threade-dly connected to the base 1 and pipe 29 isv secured to the handle 37, yit is evident that by raising the handleI relative movement will take place between tubes 29 and and cause the latter to slide in ther stuffing box. The movement of the handle 37 in an upward direction will, of course, cause the rod 2O to move upwardly with respectto tube 5 and carry with it the valve'which is secured to the vlower end thereof.` The upward movement` of tube 29 will decrease the volume. of the annular space between valve 11 and cup 30, and the air contained therein will flow between valve. l1 and cap 6 through holes 16 into the interior of tube annular space `below valve 11v through the channels provided therefor in mem'ber 6.I

It will be noted that I yhave provided passages which permit the lair to ente-r the cylinders without passing between, the cylinder Walls and the leather cups, yasis customary in this 'type of pump. By means of these air passages, the drying effect of the air on thev leather cups is overcome to a great extent, and the valves last longer.y

bled, and is comparatively free from valve troubles owing to the peculiar valve construction which reduces to a minimum the drying effect of the air.

Having now described my invention, what I claim as new is- A valve adapted for use inanair pump,

comprising anannular mounting ring, ya leather cup valvemember ,mounted insaid ring, means cooperating with the ,annular mounting ring for permitting thel free passage of air therethrough in one direction. and for preventing the flow yof air therethrough in the opposite direction, said means comprising a member having a flange on one end thereof, a boss extending ,through said mounting ring, `shoulders on said flange for preventing the ring from contacting with the flange, a sealing washerY secured to lthe end of the boss opposite from the flange, and a nut for holding said washer in place. Y n

In testimony whereof I aflix my signature.

JOSEPH P. SHEVLIN. 

